Geophysical methods are techniques used to study the Earth's physical properties and structure. These methods often involve measuring variations in the Earth's magnetic, gravitational, electrical, or seismic fields. By analyzing these measurements, scientists can infer information about subsurface materials, such as minerals, water, and geological formations. Common geophysical methods include seismic surveys, which use sound waves to map underground structures, and magnetic surveys, which detect variations in the Earth's magnetic field. These techniques are widely used in fields like geology, environmental science, and engineering to locate resources, assess hazards, and understand Earth's processes.